基于正交试验及CFD的消防泵叶轮优化设计

Optimization design based on orthogonal experiment and CFD on fire pump impeller

针对大流量消防泵在使用过程中效率偏低的问题,根据L18(37)正交表,选取Z,β2,,d1,b2,T2,d2等7个因素,每个因素取3个水平,设计出18种叶轮模型方案.同时,采用计算流体动力学软件Fluent对18种方案的消防泵内三维定常流动进行数值计算,并对计算结果进行极差分析,研究几何参数对消防泵性能的影响,得到了消防泵几何参数对各性能指标影响的主次顺序,并确定出最终优化模型.结果表明:随着叶片数和叶片包角的增大,消防泵效率得到显著提高,而效率与叶片进口直径呈负相关,即效率随叶片进口直径的增大而减小.同时,对扬程影响最大的因素为叶片数,扬程随叶片数的增大而显著增大,叶片出口安放角对扬程影响很小.对优选消防泵的性能试验结果表明:优选方案在设计工况点较原模型的效率提高了4.5%,满足设计要求,验证了正交设计方法的可行性.

In order to improve the efficiency of large flowrate fire pumps, the L18（37） orthogonal table was constructed by selecting Z, β2, Ф, dl, b2, T2,d2 as relevant factors. With three levels for each factor, 18 kinds of impeller model programs were established. Then, the computational fluid dynamics （CFD） software Fluent was used to analyze their internal steady flow. By applying range analysis, the influence of the geometric parameters on the fire pump performance were analyzed, obtaining the im- pact order of these parameters on performance, and ultimately the optimal model was determined. The results show that more blades and larger wrap angle can improve the pump efficiency significantly while the efficiency is negatively correlated with the blade inlet diameter. At the same time, the biggest fac-tor affecting the head is the number of blades with more blades resulting in higher head. The impact of blade outlet angle on the head is very small. Experimental results show that the efficiency of the opti- mized pump is higher than the original model by 4.5 % at the design point, and also higher than the national standards, which meets the design requirements. The feasibility of the method is verified by the orthogonal design method.